08/04/2021 at 2:21 PM #33591Anonymous UserParticipant
The woes of the Gulf Stream
The Gulf Stream is said to be at its lowest level in 16 centuries. Little more has been learned since the release of this estimate in February: Are we on the verge of a fundamental change in global climate systems, or is it an anomaly? ?
The question is not just for residents of both sides of the Atlantic: although the which transports in the warm waters of until then back to the , in depth, the cold. It is part of a larger ocean currents, currents that play a vital role in the redistribution of from .
The authors of the study published on February 26 in have made a “reconstruction” of the evolution of the Gulf Stream from the year 400 until today on the basis of indicators of past climates trapped in sediments or in recent meteorological data. Their conclusion: the Gulf Stream, or , would have been relatively stable until the middle or the end of the 19th . It has since started to slow down. And like many other scientists before them, the authors point to the .
Like ocean currents sort of to the planet, carrying heat to the surface and in the depths, a or even a stop of these currents, would have important consequences … but difficult to predict. The last time an inversion of this “ocean conveyor belt” took place was at the end of the Ice Age: two huge ice caps. overlooking part of Europe and on one side, and on the of on the other had melted. The of fresh and colder water poured into the Atlantic had been such that the “conveyor belt” had stopped: at to slow down or even reverse the global warming underway in Europe.
Would the same scenario be to repeat with the melting of the ice cap of the ? This has been the hypothesis of researchers for two decades, but there the comparison ends: as gigantic as the amount of ice involved, it is far from that of the two ice caps of yesteryear.
Still, the impact could be felt everywhere in the , and not just with the . This could result in more frequent “anticyclonic blockages”, that is to say those atypical configurations of air currents which cause temperature or precipitation anomalies in a region. during , even weeks. Involving in turn abnormal colds for a region, and prolonged heatwaves (doubled by droughts) in the same region.
According to Stefan Rahstorf, lead author of the February, at the current rate of warming , the Gulf Stream is expected to slow down by a third by 2100. As to whether there will be a beyond which this slowdown will become irreversible, the are open.
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